1. Technical Field
The present invention relates to an optical position detecting device which optically detects a target object.
2. Related Art
As an optical position detecting device which optically detects a target object, for example, as shown in FIG. 8, an optical position detecting device is suggested in which detection light L2 is emitted toward the target object Ob via a translucent member 40 from two detection light source sections 12, and detection light L3 reflected by the target object Ob is transmitted through the translucent member 40 and is detected by a photodetector 30. In this optical position detecting device, for example, if the two detection light source sections 12 are differentially moved on the basis of a detection result in the photodetector 30, the ratio of the distance between one detection light source section 12 of the two detection light source sections 12 and the target object Ob and the distance between the other detection light source section 12 and the target object Ob is known. Accordingly, the position of the target object Ob can be detected (refer to JP-T-2003-534554 (FIG. 10)).
However, in the configuration shown in FIG. 8, in a case where the target object Ob is inside two detection light source sections 12 as shown as the target object Ob1 and in a case where the target object Ob is outside the two detection light source sections 12 as shown as the target object Ob2, there is a problem in that the ratio of the distance between one detection light source section 12 of the two detection light source sections 12 and the target object Ob and the distance between the other detection light source section 12 and the target object Ob becomes equal. For this reason, when the ratio of the distance between one detection light source section 12 of the two detection light source sections 12 and the target object Ob and the distance between the other detection light source section 12 and the target object Ob is obtained, it cannot be determined whether the distance between the two detection light source sections 12 may be internally divided or externally divided.